HIGH-INCIDENCE OF ANTIBIOTIC-RESISTANCE AMONG BACTERIA IN 4 INTENSIVE-CARE UNITS AT A UNIVERSITY HOSPITAL IN SWEDEN

The frequency of antibiotic resistance among bacteria in 4 intensive c are units (ICUs) at a university hospital in Sweden was investigated a nnually from 1993 to 1996. rin increase in ampicillin-resistant entero cocci from 1993 to 1995 was seen which was due to a shift from Enteroc occus faecalis to Enterococcus faecium. After a special infection cont rol programme was instituted, the rate of ampicillin resistance among enterococci and the number of E. faecium isolates declined during 1996 . The oxacillin resistance rates for Staphylococcus aureus were less t han or equal to 2%, while most of the coagulase-negative staphylococci (CNS) were oxacillin resistant. No vancomycin-resistant enterococci o r staphylococci were seen. The ciprofloxacin resistance rates for CNS and Enterococci spp. were high. Relatively high levels of resistance t o cefotaxime and piperacillin/tazobactam among Enterobacter spp. were also seen. During 1995 and 1996 Pseudomonas aeruginosa showed increasi ng resistance to ceftazidime, ciprofloxacin and piperacillin/tazobacta m. This was due to an outbreak among rather few patients. The overall resistance rates for Gram-negative bacteria were low for aminoglycosid es and imipenem. From 1993 to 1996 the total antibiotic consumption de creased by 27% in the whole hospital and 16.5% in the ICUs. However, t he reduced antibiotic consumption was paralleled with a 23% decrease i n the total number of patients treated in the hospital from 1993 to 19 96. In contrast there was an 11.5% increase in the number of ICU patie nts treated during this period. The conclusion is that all ICUs within a hospital should have a programme for 'on-line' antibiotic resistanc e surveillance of drugs used in that unit in order to change the empir ic treatment when there is an increase in antibiotic resistance. It is also important to survey the antibiotic consumption in the ICUs in or der to avoid further selective pressure on bacteria showing increased resistance rates.